Artificial and supplemental lighting in e.g. a greenhouse typically involves use of an illumination system for stimulating plant growth, the illumination system comprising a plurality of high power light sources. Different types of light sources, having different light spectrum and providing different effects on growth stimulation, may be included, such as light sources based on metal halide (MH) or high intensity discharge (HID) which includes high pressure sodium (HPS). Using metal halide based lighting typically promotes shorter, bushy growth; whereas high pressure sodium based lighting in comparison typically tend to produce taller and stretched plants.
Recently, much progress has been made in increasing the brightness of light emitting diodes (LEDs). As a result, LEDs have become sufficiently bright and inexpensive to serve also for artificial lighting in e.g. a greenhouse environment, additionally providing the possibility of emitting light with adjustable light spectrum. By mixing differently colored LEDs and adjusting their individual intensity a desired light spectrum may be obtained. An adjustable lighting system typically comprises a number of primary colors, for one example the three primaries red, green and blue. The light spectrum of the generated light is determined by the colors of the LEDs that are used, as well as by the mixing ratios of the intensity of light from LEDs of different colors. Thus, each LED of a LED based illumination system may be individually controlled such that a light spectrum of the overall emitted light may be conveniently adjusted. Furthermore, by using LEDs it is possible to decrease the energy consumption, a requirement that is well in line with the current environmental trend. Additionally, using LED based illumination system minimizes the amount of light source generated heat which is specifically suitable in an environment where temperature control is desirable. An example of an LED based illumination system is disclosed in WO2008118080, comprising a light sensor communicatively coupled to a processor, where the processor implements a control algorithm for modulating and improving plant growth and attributes by adjusting the light spectrum emitted by the illumination system.
Document WO2008118080 shows a promising approach in relation to artificial lighting in a greenhouse environment, however, it would still be desirable to further optimize the artificial lighting systems, to be able to improve the growth process of a plant, specifically improving handling and implementation of artificial lighting systems for plants arranged in a greenhouse environment. For example, in e.g. a greenhouse there may be hundreds or thousands of light-emitting devices arranged to modulate and improve the growth of plants arranged in the greenhouse. During installation of the light-emitting devices, it is cumbersome and time-consuming to keep track of which light-emitting device is mounted at what position in a grid of light-emitting devices.